Automatic feed-water regulator.



A. R. DODGE.

AUTOMATIC FEED WATER REGULATOR.

APPLICATION FILED FEB. 12. 1912.

Llmh Pamedsept. 21, 1915.

Witnesses.: Inventor-t,

I I y .squtn.odg,

by ,i 1.1)

` Hisaqttorneg.

` citizen of the United States,

NETE@ STATES TATEN T @TTTQEO AUSTIN' R. DODGE, OF SCHENECTADY, NEW YORK,`ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPGRATION OF NEW YORK.

.AUTOMATIC FEED-WATER REGULATOR.

Specification of Letters Patent.

Patented Sept. 2li, 1915.

Application filed February 12, 1912. Serial No. 677,002.

T all 101mmt may concern.'

Be it known that I, AUSTIN R.I DODGE, a residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Automatic Feed-VVater Regulators, of which the following is a specification.

The present invention relates to feed Water regulators which are arranged to supply Water to a storage space boiler and automatically maintain a fixed level of Water therein so as to obtain the best steaming effects.

My invention is directed either to the regulation of single boilers or to boilers arranged in a battery and supplying steam to a common main or header. I have found with the governing arrangements heretofore employed that the steaming effects of' boilers are subject to Wide variations, thereby resulting` in increased and unnecessary coal consumption. In the case of boilers arranged in a battery, I have found that the amounts of steam delivered by the different boilers vary Widely both above and below the proportional amounts Which said boilers should deliver to obtain the best results. This is due chiefly to the fact that existing regulating means do not take into account the rate of iovv of the steam leaving the boiler, but depend solely or principally upon changes in Water level, said changes taking place only after the changed demand for steam has existed for some time. After this delay, the regulating mechanism operates and generally, or at least in many cases, supplies either too much or too little Water to the boiler.

My invention has for its object to provide an improved mechanism for automatically controlling the supply of Water or other .liquid to a vapor generator Which is free from the objections above noted.

' In carrying out my invention I locate an agent or means in the discharge main of the boiler, such for example as an impact tube, which as the rate of flow of the steam passing through the main changes due to a variation in demand for steam, causes a corresponding increase in pressure in a pipe connected thereto if the velocity of Viiovv in" creases and a corresponding decrease or lowering of the pressure if the velocity of flow decreases. l

Located in some suitable place, such as the chamber of the Water column of the boiler, is a diaphragm or other means that is sensitive to pressure changes. Acting on one side of the diaphragm is the pressure due to the action of said agent or means and acting in opposition thereto and on the other side thereof is the boiler pressure as it exists in the Water column or chamber containing the diaphragm. Under conditions of no iiow'in the main the forces acting on the diaphragm are practically equal and the diaphragm Will take a zero position. By making the diaphragm of sutiicient size a relatively large force is available even though the increase in pressure over the boiler pressure due to the agent is small.

To the movable part of the diaphragm or other means is connected a member which actuates a regulator that controls the admission of Water to the boiler either directly or indirectly.' |Ihat is to say, a valve may be located in the supply pipe delivering Water to the boiler and moved by the diaphragm or the valve may be in a steam main Which supplies steam to a prime mover driving a feed pump. In order to actuate this valve in such manner that it may have intermediate positions and also to avoid calling on the diaphragm to perform an excessive amount of work, the valve is actuated by a motor, such for example as a hydraulic motor, and the pilot valve of the motor is controlled by the diaphragm. 'Ihe 'actions of the motor piston and pilot valve are modified by a follow-up device which prevents overtravel of the motor piston and restores a sleeve containing the pilot valve ports to. the midposition of said ports Where they are covered by the pilot valve.. As. the pilot valve and the diaphragm are mechanically united, the follow-up device cannot act directly on the valve since it would mean opposing the action of the diaphragm. I avoid this by surrounding the pilot valve with the ported sleeve aforesaid and connect it to the motor piston by suitable means. As the diaphragm referred to above is made of spring metal it has a tendency to return to its initial position Whenever the opposing forces thereon' are equalized.

Since it is not always possible to cause the said agent to create exactly the amount of pressure at all times required to move the diaphragm or give to the diaphragm the exact returning force desired, I provide a means such as a float in the water column that takes into account the level of water in the boiler and which is capable of modifying the action of the diaphragm as regards the admission of water to the boiler. It is also capable of directly regulating the action of the water admittin means independently of the diaphragm. uch a device is of the greatest importance when for example the prime mover receiving steam from the boiler is suddenly shut down. This means that the pressure difference acting on the diaphragm no longer exists and hence it has no control over the admission of water Ato the boiler, whereas the boiler keeps. on steaming and blowing olf steam to the open air. Under these conditions the ioat will assume control of the water supply to the exclusion of the diaphragm. By properly arranging the diaphragm and the device responsive toy changes in water level, such for example by connecting them to the same lever, as will appear more fully hereinafter, either one or both of said means will be capable of controlling the supply of water to the boiler or both may operate simultaneously, one modifying the other.

Instead of using an impact tube and diaphragm, I may substitute' therefor a pivoted or swinging shutter or device of valvelike construction that is located in the main discharging steam from the boiler which normally tends to close and whose angular position bears a direct relation to the rate of steam flowing through the main. That is to say, when the flow is small the 'valve o ening is`less than when the flow is large.

o the spindle of this device is connected a system of arms and levers which coperate with the float above referred to, the remainder o'f the apparatus being the same.

In the accompanying drawing which illustrates one of the embodiments of my inventi'on, Figure 1 is a view`partiallyin elevation and partially inl section of'a boiler equipped with my improvedl feed water regulating means; and Fig. 2 is a sectional view of a modification.

1 indicates a boiler which may be of any suitable and ordinary construction and is provided with a water column or equivalent device 2 that is connected at its lower end by the pipe 3 to the under side ofthe boiler and the pipe 4 with the steam or storage space of the boiler. Located within the chamber of the water column is a main slotted lever 5, the upper end of which is connected tothe movable part of a metallic diaphragm 6 made after the fashion of a bellows. The lower end of the lever is connected by a rod 7 tothe pilot valve of a` motor for controlling the admission of water to the boiler as will appear later. The connections between the lever 5 and the movable part of the diaphragm and the rod 7 are such as to permit the parts to move freely, thereby avoiding binding and sticking.

8 indicates a secondary or auxiliary lever which is pivoted at 9. One end of the auxiliary lever carries the fulcrum 10 for the main lever 5, said fulcrum being located in the cam slot in said lever. The other end of the auxiliary lever is connected by a rod 11 lwith a float 12 located in the water column, said float being responsive to changes in level of the water in the boiler.

13 indicates a main discharging steam from the boiler. Located in the main is an agent such as impact tube 14: of suitable shape and construction; as shown it comprises a cone or funnel or tube facing the column of steam issuing' from the boiler. This cone or funnel or tube is connected by the pipe 15' with the interior of the diaphragm 6. Since the diaphragm is located in the steam containing chamber of the water column it is acted upon differentially by two forces, that due to the boiler pressure and that due to the action of the impact tube. The pressure due to this impact tube or agent varies with changes in the rate of flow of the steam issuing from the boiler. By making the diaphragm of suitable proportions, a relatively large force is available for moving the mainlever 5. Under conditions of maximum flow tlie pressure difference due to the action of the impact tube on the diaphragm may, as an illustration, amount to two pounds. This pressure acting on a large diaphragm will obviously give a force depending upon the surface area of the diaphragm.

16 indicates a pipe which may convey water directly to the boiler or it may convey steam to the prime mover for driving a feed pump. Located in the pipe is a valve 17 which is actuated by the motor piston 18, the latter being located in a cylinder 19. The admission of water or steam to the motor from the pipe 20 is controlled by a pilot valve 21 which is actuated by the rod 7. Surrounding the pilot valve is a ported sleeve 22 that is actuated by the rod 23, said rod being connected to a lever 24, the latter being linked to a lever 25 which engages a pin 26 on the piston rod. Assuming that the pilot valve is moved to the right, the ported sleeve remaining stationary, fluid under pressure will be admitted by the pipe 20 to the right-hand end of the cylinder causing the pistonr18 to move to the left. This movement of the piston causes the parts 23 to 26 to move the ported sleeve in a direction to cause the headsof the pilot valve to cover the ports and thus stop` the motor piston and hold the valve 17 in fixed position. The exhaust from the motor takes place through the ports 27 located at the ends of the pilot valve.

Assuming a certain water level and an increased demand for steam as soon as the rate of flow of steam from the boiler increases the pressure due to the impact tube acting on the inside of the diaphragm will force the upper end of the main lever to the left and since the position of the fulcrum 10 remains unchanged, the pilot valve will be moved in a direction to cause more water to enter the boiler. As'before stated the valve 17 controlled by thepilot valve and motor may,

admit water directly or vary the speed ofv a prime mover which drives 3a feed pump. Conversely, if the rate of flow of the steam from the boiler decreases, the steam pressure in the chamber of the water column acting against the decreased pressure due to the impact tube will force the upper end of the main lever 5 to the right, thereby moving the pilotvalve in a direction to cause the motor piston 18 to decrease the opening of the valve 17. If now the water level increases above the predetermined point, the float 12 will rise and change the position of the fulcrum 10 that travels in the cam slot in the main lever 5. This cam slot is `so shaped and the fulcrum so positioned that the pilot valve will be moved in a direction to cause the motor to decrease the opening ofthe valve 17. T he diaphragm and float may act simultaneously or separately depending upon the conditions of operation. On the other hand if the water level decreases below the normal the ioat 12 is depressed'and the fulcrum 10 is moved upward in the cam slot thereby causing the rod 7 to move the pilot valve in a direction to cause the motor to open the valve 17 to a greater or less extent. Owing to the use of the impact tube, the

`means admitting water to the boiler are rendered exceedingly sensitive and instead of waiting until a decided change in water level takes place, the parts respond instantly thereby avoiding all the days or lagging action. The impact tube can never cause an oversupply oran undersupply of water to the boiler because of the modifying action of the float 12 and its associated parts.

Referring to Fig. 2,` I have shown' a slight modification of my invention wherein a pivoted valve-like structure 30 is provided and p located in the main 13. This valve is mounted on a spindle 31 to the end of which is connected an arm 32, so that as the valve 30 moves to and fro depending upon the changes in the rate of How of the steam leaving the boiler, the arm will. be moved. To the lower end of the arm is connected a rod 33 which is pivotally attached to the upper end of the main slotted lever 5. This lever is provided with a fulcrum 10 carried by the auxiliary lever 8 which is connected to the float 12 as above described. The lower end of the main lever is connected by the rod 7 to the pilot valve. In other words, I have substituted for the diaphragm and the impact tube 14 another form of device which is responsive to changes in the rate of flow of the steam issuing from the boiler and have connected this meansn with the upper end of the main lever 5 in a manner to cause it to move as the rate of flow of the steam changes. As the operation of the apparatus from this point on vis the same as that previously described, further description seems unnecessary.

In accordance with the provisions of the patent statutes, Ihave described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that they apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desireto secure by Letters Patent of the United States, is

1. In combination, a vapor generator, a means for supplying liquid thereto to be vaporized, a kregulator for said means, a lever for actuating theregulator, a means sensitive to changes in the rate of flow of vapor from the generator for moving the lever, a fulcrum for the lever, and a device sensitive to variations in the level of the liquid in the generator for changing the position of the fulcrum.

2. In combination, a vapor generator, a

means for supplying liquid thereto to be vaporized, a regulator for the said means, a lever, a means sensitive to changes in the rate of flow of vapor from the generator which acts on one end of thelever, a connec. tion from the lever to the regulator, an adjustable fulcrum for the lever, and a device sensitive to variations in the level'of the liquid in the generator for changing the position of the fulcrum.

3. In combination, a vapor generator, a` means for supplying liquid thereto, a valve controlling the means, a motor for actuating the valve, a pilot valve for the motor, a follow-up device for the motor, a floating lever for moving the pilot valve and to which the stem of theI valve is connected, a device responsive to changes inA the ratepf flow of the vapor issuing fromV the. generator, adevice responsive to changes in `level' ofthe liquid in the generator, and means connect ing each of said devices to the floa ting lever.

4. In combination, a vapor generator, means supplying liquid thereto, a regulator therefor, a discharge main for the generator, an agent located in the main which creates a pressure that varies with changes in the rate of flow of vapor through the main, a diaphragm which is exposed on one side to the pressure of the vapor generated and on the other to a higher pressure due to the action of the agent, and means connecting the diaphragm With the regulator.

In combination, a vapor generator, means supplying liquid thereto, a regulator therefor, a discharge main for the generator, an agent located in the main which creates a pressure that varies With changes in the rate of flow of vapor through the main, a diaphragm -which is exposed on one side to the pressure of the vapor generated and on the other to a higher pressure due to the action of the agent, means connecting the diaphragm With the regulator, and a means responsive to changes of level of the liquid in the generator for modifying action of the diaphragm on the regulator.

G. In combination, a vapor generator, means supplying liquid thereto, a regulator therefor, a discharge main for the generator, an agent located in the main which creates a pressure that varies With changes in the rate of flow of vapor through the main, a diaphragm which is exposed on one side tothe pressure of the vapor generated and on the other to a higher pressure due to the action of the agent,`a lever acted upon by the diaphragm, which moves the regulator, and a means responsive to changes of level of the liquid in the generator for modifying the action of the lever on the regulator.

7. In combination, a vapor generator, means supplying liquid thereto, a regulator therefor, a discharge main for the generator, an agent located in the main which creates a pressure that varies with changes in the rate of flow of vapor through the main, a means acted upon by the pressure due to the action of the agent, a lever which is moved by the means for controlling the regulator, a fulcrum for the lever, and means responsive to changes in level of the liquid in the generator for adjusting the fulcrum to modify'the action of the first named' means.

8. In combination, a vapor generator, means supplying liquid thereto, a regulator for the liquid `supply comprising a valve and a motor for actuating it, a pilot valve for the motor, a ported sleeve that surrounds the pilot valve, means connecting a movable part of the motor and the sleeve, a lever for moving the pilot valve, means responsive to variations in the rate of flow of the vapor issuing from the generator for moving the lever, and a device responsive to changes in level of the liquid in the generator Whichcooperates With the means to move the lever.

9. In combination, a vapor generator, means supplying liquid thereto, a regulator for the liquid supply, a main conveying vapor from the generator, an impact tube therein, a means acted upon by the fluid pressure due to the said tube, a chambered vessel containing the means Which chamber is in communication With the interior of the generator at points above and below the liquid level therein, the pressure in sai chamber acting in opposition to said means, and a device in said chamber responsive to changes in level of the liquid in the generator which coperates With the means to move the regulator.

10. The combination With a steamI boiler, of a feed Water pipe therefor, a valve controlling said pipe, a floating lever for operating said valve connected at one end thereto, and `means forl operating said ioating lever comprising a device responsive to the rate of flow of steam from said boiler and a seco-nd device responsive to changes in thelevel of Water in the boiler.

' 11. The combination With a steam boiler, of a feed Water pipe therefor, a valve controlling said pipe, a floating lever for operating said valve connected at one end thereto, and means for operating said floating lever comprising a device responsive to the rateiof floW of steam from said boiler connected to the other end of said lever, and a device responsive to changes in the level of Water in the boiler connected at an intermediate point to lsaid lever.

In Witness whereof,'I have hereunto set my hand this 9th day of February, 1912.y

AUSTIN R. DODGE.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

